The present invention relates to trim tabs mounted to the transom or underside the hull of a boat. In particular, the trim tabs are molded composite material elements shaped to provide light weight and enhanced lift characteristics.
Trim tabs typically have been in the form of flat stainless steel plates that are pivotally attached to the transom or hull of the boat. Trim tabs of different sizes are used, depending upon the size of the boat.
In one typical configuration, at least one trim tab is pivotally mounted on the left or port side and at least one trim tab is pivotally mounted on the right or starboard side of the transom. In other cases, a single center mounted trim tab is used. The trim tabs are raised and lowered by a drive mechanism. Earlier trim tab systems used mechanical jack screws to raise and lower the trim tabs. Currently available systems use either hydraulic or electromechnical actuators to raise and lower the trim tabs.
Trim tabs are used to provide additional boat control for reasons such as uneven load distribution in the boat, controlling bow attitude in various water conditions, and trimming the boat out of the water faster in conditions such as shallow water operation. Depending on the type of boat and the number and position of occupants, the attitude (or side-to-side angle along the keel) can tilt left or right. Trim tabs can improve boat performance by leveling the boat. Trim tabs can also be used to increase top end speed, to improve “hole-shot”, and to provide a drier ride by keeping the nose down and the boat up on plane.